Hydrogen Peroxide 50% w/v

For Laundry Bleaching

Hydrogen Peroxide is the bleach of choice for wool, silk and certain bleaching resin finished textiles such as crease resistant rayon and non-iron cottons.

Hydrogen peroxide is an oxidising bleach but is slow in action. As purchased it has very limited bleaching powers and must be activated with added alkali.

Directions

AUTOMATIC DOSING SYSTEMS may use up to 2.0 ml of Hydrogen Peroxide 50% per kg of wash load. Injection must be delayed until water is present.

STOCK SOLUTIONS of 10 vol. (3% hydrogen peroxide w/v) are prepared by adding 625ml of 197 vol. hydrogen peroxide to 9.375L of cold water. NOTE: Stock solutions of hydrogen peroxide decompose more rapidly than sodium hypochlorite and only enough for one day should be made at any one time. The presence of dust hastens decomposition therefore dust should be excluded as far as possible.

BLEACHING cotton with hydrogen peroxide may be accomplished in the presence of magnesium silicate in the wash with temperature below 60C. As a starting point use 1.5L of 10 vol. stock solution per 100kg; 3.5L per 100kg should be regarded as a working maximum. Bleaching in the rinse with hydrogen peroxide is ineffective due to short cycles and insufficient alka- linity.

WOOLLENS may be bleached in a bath made by dissolving 130g sodium silicate (waterglass) in 1L hot water then adding to 100L cold water. Add 6L of 10 vol. or 625ml of 197 vol. hydrogen peroxide. Soak woollens for 12 to 16 hours seeing that they are properly immersed.
SPOTTING with 10 vol. hydrogen peroxide may be effective but normally adding a couple of drops of ammonia to make it alkaline greatly boosts the performance. Apply for up to 15 minutes. If prolonged treatment is required make a bath as described for woollens above. When hydrogen peroxide has dried into a garment it must be rewashed to avoid tendering.